The autumn statement contains little for Liberal Democrats to applaud. Party voices on social media were quick to claim victory in the progress on the basic rate threshold, alongside action on tax perks for the wealthy – such as the pension tax relief allowance – as far as they go. But when, only weeks ago, Liberal Democrat leaders promised not to balance the books on the backs of the poorest, we are in danger of not living up to our own expectations. Serious attempts to introduce a suite of wealth taxes to ensure a fair spread of the load appear to have been negotiated away. More concerning is the disproportionate take from poorer households.

Long-term economic failings have led to a false welfare debate. Tory Aunt Sallies on the under-25s, large families and – indeed – all those on in-work benefits, have been countered by the one reduction most (not all) Lib Dems would tolerate: fewer perks for wealthy pensioners. None have happened. What is lacking from the equation is the most efficient way to reduce the welfare budget: reform and grow the economy so fewer people are left in a state of dependency. Instead of green growth, George Osborne's medicine of Jeremy Clarkson-lite, replete with repellent, inflammatory rhetoric about welfare recipients, is toxic; Liberal Democrats would do well not to avoid contamination. A rejection of the language used in the statement is the least that should be done.

The alternatives were there. The already trimmed tax credits budget is unnecessarily swollen to the tune of up to £4bn (see the Commission for Living Standards report), thanks to the absence of a living wage policy, especially in those sectors that can afford it. That is one measure that ensures that work pays. If government wished to come up with other progressive (or less regressive) measures that can go somewhere towards tightening the load, there are plenty out there – as the CentreForum has set out.

Meanwhile, Osborne asked us to judge him on deficit reduction. By all accounts, he has failed – because Plan A has failed. In circumstances such as these, why should a government not be tough on failing ministers?

The truth is that Plan C is tacitly being implemented. However, there is no mandate and no grounds in the coalition agreement for attacks on the most vulnerable. Members of the social liberal majority in the Liberal Democrats don't support penalising all those who rely on the welfare society for support. In an online survey of our members last week, the alternatives of the mansion tax (a first step to a proper land value tax), wealth taxation and an end to unaffordable state-sponsored perks for rich pensioners, backed up by sensible relaxation of unachievable deficit reduction deadlines, enjoy much wider support.

Following the departure of the hapless Richard Reeves, some signals from Clegg's office are encouraging, but these may come too late for the increasing numbers of social liberals agitating for special conferences against the more egregious government announcements. More still are seeking leadership from the party they last saw in 2010. Some are finding it in the increasing rebelliousness of the Lords, until it is further stuffed in the new year. Others will find it in the comfort of their sofas, rather than the bundle of Focus leaflets.

The party desperately needs to identify a clear official economic narrative in time for 2015. None appears forthcoming, and the economy is noticeably absent from the lengthy list of current Liberal Democrat policy groups. Until that voice is articulated, social liberal support will ebb away from the coalition and those at the head of it. Without the start of the inevitable exit strategy – yet – the choice for the Liberal Democrat leadership is stark. Find an authentic Liberal Democrat voice. They will find people who will listen.